Surgical stapling device with dissecting tip

ABSTRACT

A dissecting tip is provided for use with a surgical stapler or instrument. In one embodiment, the dissecting tip is secured to the end effector of the surgical instrument, e.g., to the cartridge assembly. The dissecting tip extends distally from the end effector and is configured to dissect or separate target tissue from certain tissue, e.g., adherent, connective, joined or other tissue.

This application is a divisional application of U.S. application Ser. No. 10/764,103, filed Jan. 23, 2004, which is incorporated herein in its entirety by reference

BACKGROUND

1. Technical Field

This application relates to a surgical stapling device. More particularly, this application relates to a surgical stapling device having an improved tip construction for accessing and/or separating tissue.

2. Background of Related Art

Surgical staple or fastener applying devices for joining tissue are well known. Typically, such devices include opposing jaw structure for grasping and clamping selected tissue, wherein one of the jaws of the opposing jaw structure includes a cartridge which houses a plurality of staples or fasteners. In some instruments, a knife is provided to cut tissue which has been joined by the staples or fasteners.

Linear surgical stapling devices, for example, include two elongated members which are relatively moveable to capture or clamp tissue. Typically one of the members includes a cartridge which houses a plurality of staples arranged in two or more linear rows and the other member includes an anvil having a plurality of staple forming pockets for receiving and forming the legs of the staples. A knife is movably positioned between the linear rows of staples such that when the stapling device is positioned about tissue and actuated, the tissue is joined and/or simultaneously or nearly simultaneously cut. tissue before the procedure can continue. Currently, a surgical device separate from the stapling device is used to dissect or separate the certain tissue from the target tissue before the target tissue and/or the adherent certain tissue is operated upon. Also, it is a known practice to attach a guide or carrier tube to the distal end of the anvil and to use a separate instrument to pass the tube around the target tissue or structure. The tube is also used to move the back wall of the target tissue into the jaws of the stapling device. The tube is removed after the staple is in proper position and then the stapler is fired. These procedures require extra steps and devices and can be time consuming and expensive especially during endoscopic procedures.

Accordingly, a continuing need exists in the art for a device which can be used not only to join and cut tissue but also to separate or dissect certain, e.g., adherent, tissue from target tissue.

SUMMARY

In accordance with the present disclosure, a dissecting tip is provided for use with a surgical stapling device and, especially, a linear surgical stapling device, including an end effector having an anvil assembly and a cartridge assembly. The dissecting tip is supported on the end effector, preferably, on the distal end of the anvil assembly. The dissecting tip can instead or also be supported on the distal end of the cartridge assembly. The dissecting tip can be positioned to extend distally from the anvil assembly and includes a body having an outer surface, an inner surface and a distal tip. The body may assume a variety of configurations. For example, the body may include inner and/or outer surfaces which are curved along the longitudinal and/or transverse axis of the anvil assembly and extend downwardly towards the cartridge assembly. In another preferred embodiment, the inner and/or outer surfaces are substantially flat. In yet another preferred embodiment, the inner and/or outer surfaces include a pair of flat sections interconnected by a curved transition section. Preferably, the width of the dissecting tip decreases from the proximal end of the dissecting tip to the distal end of the dissecting tip. The distal tip of the dissecting tip is preferably rounded and blunt to prevent snagging, pulling and/or cutting of tissue.

The dissecting tip functions to dissect or separate target tissue and certain tissue. As discussed above, “certain tissue” includes adherent, connective, joined or other tissue. This is preferably accomplished by passing or pressing the outer surface of dissecting tip against the target tissue and pushing the distal tip of the dissecting tip behind the certain tissue such that the certain tissue is positioned adjacent the inner surface of the dissecting tip. Preferably, the dissecting tip is located and dimensioned to permit access through a trocar cannula assembly sized to receive the surgical stapling instrument without the dissecting tip.

BRIEF DESCRIPTION OF THE DRAWINGS

Various preferred embodiments of the presently disclosed dissecting tip are described herein with reference to the drawings, wherein:

FIG. 1 is a side top perspective view of a surgical stapling device including one preferred embodiment of the presently disclosed dissecting tip attached to the end effector thereof;

FIG. 2 is an enlarged view of the indicated area of detail shown in FIG. 1;

FIG. 3 is a side view of the end effector with portions broken away and of the dissecting tip of the surgical stapling device shown in FIG. 1 with the end effector in the open position adjacent target tissue and certain tissue which is adhered to the target tissue;

FIG. 4 is a side view of the anvil assembly shown in FIG. 3 with the dissecting tip positioned partially between the certain tissue and the target tissue;

FIG. 4 a is a side view of the anvil assembly and dissecting tip shown in FIG. 4 positioned fully between the certain tissue and the target tissue;

FIG. 4 b is a side view of the dissecting tip and end effector shown in FIG. 3 with certain tissue positioned between an open anvil assembly and cartridge assembly;

FIG. 5 is a side view of the dissecting tip and end effector shown in FIG. 4 b with certain tissue positioned between a clamped anvil assembly and cartridge assembly;

FIG. 5 a is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 1;

FIG. 5 b is a bottom view of the dissecting tip and end effector shown in FIG. 5 a;

FIG. 5 c is a front view of the dissecting tip and end effector shown in FIG. 5 b;

FIG. 5 d is a side perspective view from the front of the presently disclosed dissecting tip dissector shown in FIG. 1;

FIG. 5 e is a side view of the dissecting tip shown in FIG. 5 d;

FIG. 6 is an enlarged top side perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 6 a is a side view of the dissecting tip and end effector shown in FIG. 6;

FIG. 6 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 6;

FIG. 6 c is a bottom view of the dissecting tip and end effector shown in FIG. 6 b;

FIG. 6 d is a front view of the dissecting tip and end effector shown in FIG. 6 c;

FIG. 6 e is a side top perspective view from the front of the presently disclosed dissecting tip shown in FIG. 6;

FIG. 6 f is a side view of the dissecting tip shown in FIG. 6 e;

FIG. 7 is an enlarged side top perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 7 a is a side view of the dissecting tip and end effector shown in FIG. 7;

FIG. 7 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 7;

FIG. 7 c is a bottom view of the dissecting tip and end effector shown in FIG. 7 b;

FIG. 7 d is a front view of the dissecting tip and end effector shown in FIG. 7 c;

FIG. 7 e is a side top perspective view from the front of the presently disclosed dissecting tip shown in FIG. 7;

FIG. 7 f is a side view of the dissecting tip shown in FIG. 7 e;

FIG. 8 is an enlarged side perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 8 a is a side view of the dissecting tip and end effector shown in FIG. 8;

FIG. 8 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 8;

FIG. 8 c is a bottom view of the dissecting tip and end effector shown in FIG. 8 b;

FIG. 8 d is a front view of the dissecting tip and end effector shown in FIG. 8 c;

FIG. 8 e is a side perspective view from the front of the presently disclosed dissecting tip shown in FIG. 8;

FIG. 8 f is a side perspective view from the rear of the dissecting tip shown in FIG. 8 e;

FIG. 8 g is a side view of the dissecting tip shown in FIG. 8 e;

FIG. 9 is an enlarged top side perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 9 a is a side view of the dissecting tip and end effector shown in FIG. 9;

FIG. 9 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 9;

FIG. 9 c is a bottom view of the dissecting tip and end effector shown in FIG. 9 b;

FIG. 9 d is a front view of the dissecting tip and end effector shown in FIG. 9 c;

FIG. 9 e is a side perspective view from the front of the presently disclosed dissecting tip shown in FIG. 9;

FIG. 9 f is a side view of the dissecting tip shown in FIG. 9 e;

FIG. 10 is an enlarged side perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 10 a is a side view of the dissecting tip and end effector shown in FIG. 10;

FIG. 10 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 10;

FIG. 10 c is a bottom view of the dissecting tip and end effector shown in FIG. 10 b;

FIG. 10 d is a front view of the dissecting tip and end effector shown in FIG. 10 c;

FIG. 10 e is a side perspective view from the front of the presently disclosed dissecting tip shown in FIG. 10;

FIG. 10 f is a side view of the dissecting tip shown in FIG. 10 e;

FIG. 11 is an enlarged side perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 11 a is a side view of the dissecting tip and end effector shown in FIG. 11 ;

FIG. 11 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 11;

FIG. 11 c is a bottom view of the dissecting tip and end effector shown in FIG. 11 b;

FIG. 11 d is a front view of the dissecting tip and end effector shown in FIG. 11 c;

FIG. 11 e is a side perspective view from the front of the presently disclosed dissecting tip shown in FIG. 11;

FIG. 11 f is a side view of the dissecting tip shown in FIG. 11 e;

FIG. 12 is an enlarged side top perspective view from the front of the end effector of a surgical stapling device including another preferred embodiment of the presently disclosed dissecting tip;

FIG. 12 a is a side view of the dissecting tip and end effector shown in FIG. 12;

FIG. 12 b is a top view of the dissecting tip and end effector of the surgical stapling device shown in FIG. 12;

FIG. 12 c is a bottom view of the dissecting tip and end effector shown in FIG. 12 b;

FIG. 12 d is a front view of the dissecting tip and end effector shown in FIG. 12 c; and

FIG. 12 e is a side perspective view from the front of the presently disclosed dissecting tip shown in FIG. 12;

FIG. 12 f is a side view of the dissecting tip shown in FIG. 12 e;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the presently disclosed surgical stapling device with dissecting tip will now be described in detail with reference to the drawings wherein like reference numerals designate identical or corresponding elements in each of the several views.

In the description that follows, the term “proximal”, as is traditional, will refer to the end of the stapling device closest the operator and the term “distal” will refer to the end of the stapling device furthest from the operator.

FIG. 1 illustrates a linear surgical stapling device shown generally as 10 including an end effector 12 having one preferred embodiment of the presently disclosed dissecting tip, here generally designated 14, supported thereon. Stapling device 10 also includes a handle assembly 16 and an endoscopic portion 18. End effector 12 forms part of a disposable loading unit or single use loading unit (SULU) 20. With the exception of dissecting tip 14, the remaining components of surgical stapling device 10 are substantially as described in U.S. Pat. No. 5,865,361 (“'361 patent”), U.S. Pat. Nos. 6,079,606, 6,241,139, 6,330,965 and 6,669,073 which are incorporated herein in their entirety by reference. It is contemplated that the presently disclosed embodiments of the dissecting tip may be used in association with other known linear stapling devices of both endoscopic and open construction. These devices include articulating and non-articulating devices as well as reusable and non-reusable devices. Examples of such devices are disclosed in U.S. Pat. Nos. 6,202,914, 6,250,532, 6,109,500, 6,032,849, 5,584,425, 5,540,375, 5,554,169, 5,507,426, 5,482,197, which are also incorporated herein in their entirety by reference. In light of the comments above, only the preferred embodiments of the dissecting tips disclosed herein will be discussed in detail in this application.

FIGS. 1-5 c illustrate one preferred embodiment of the presently disclosed dissecting tip in combination with a surgical stapling device 10. As discussed above, surgical stapling device 10 includes a handle assembly 16, an elongated body or endoscopic portion 18, and a SULU 20. Briefly, handle assembly 16 includes a stationary grip member 22, a pivotable trigger 24, an articulation lever 26, a rotation knob 27 and return knobs 28. SULU 20 is adapted to be releasably attached to elongated body portion 18 and includes a proximal body portion 32 and end effector 12. End effector 12 is pivotally attached to proximal body portion 32 to facilitate articulation of end effector 12 in relation to proximal body portion 32.

End effector 12 includes an anvil assembly 34 and a cartridge assembly 36 which houses a plurality of linear rows of staples. Anvil assembly 34 and cartridge assembly 36 are movable, here, pivotal in relation to each other between an open position and a clamped or approximated position. Pivotable trigger 24 is actuable through an actuation stroke or strokes to move anvil assembly 34 in relation to cartridge assembly 36 between the open position and the clamped position and to eject staples from cartridge assembly 36. The operation of each of these components is described in greater detail in the '361 patent and will not be discussed in further detail herein.

Dissecting tip 14 is secured to a distal end of the end effector 12. Alternately, dissecting tip may be integrally formed with end effector 12 or end effector 12 and dissecting tip 14 may be of monolithic construction. In one preferred embodiment, dissecting tip 14 is secured to a distal surface of anvil assembly 34 which is contiguous with a tissue contact surface 34 a of anvil assembly 34. Dissecting tip 14 is preferably formed from a surgical grade metal or plastic and is attached to anvil assembly 34 using any known suitable fastening technique, e.g., adhesives, welding, soldering, brazing, pins, etc. Alternately, other known surgically approved materials may be used to construct dissecting tip 14. In this preferred embodiment, dissecting tip 14 includes a curved preferably smooth inner surface 14 a, preferably also a curved, smooth outer surface 14 b and a rounded preferably thin blunt tip 14 c. The curved surface can be formed by any suitable radius. A one inch radius has been found suitable for certain applications. Curved inner surfaces may be formed by plural curved radii. Smooth surfaces prevent dissecting tip 14 from snagging, pulling and/or cutting tissue. Inner surface 14 a of dissecting tip 14 extends downwardly towards cartridge assembly 36 to a location beyond the distal end of cartridge assembly 36. By extending dissecting tip 14 beyond cartridge assembly 36, access to adherent tissue is improved and visualization of the tip to confirm proper position and that dissection of the adherent tissue is completed is permitted. The width of dissecting tip 14 decreases from its proximal end to its distal end and at its greatest width is smaller than the width of cartridge assembly 36. Desireably there are substantially smooth blends or transitions from the dissecting tip to the portion(s) of the jaw structure to which the tip is secured or from which it extends. When anvil assembly 34 and cartridge assembly 36 are in the clamped or approximated position, dissecting tip 14 is spaced from a distal angled tissue guide surface 36 a of cartridge assembly 36. Preferably, the space therebetween is at least the same, or preferably greater, e.g., two times greater, than the gap between the tissue contacting surfaces of the anvil and cartridge assemblies when they are approximated. However, there may be instances when it may be desired to have less space between the dissecting tip and the tissue guide surface of the cartridge, for example when it is desired to compress tissue there.

Referring now to FIGS. 3-5, when surgical stapling device 10 is used to dissect certain tissue 40, e.g., blood or airway vessels, from target tissue 42, e.g., stomach, lung, etc., curved outer surface 14 a of dissecting tip 14 can be pressed or passed against target tissue 42 and slid behind certain tissue 40, e.g., adherent tissue, to separate and/or dissect tissue 40 from, for example, adherence with target tissue 42. Positioning of dissecting tip 14 behind certain tissue 40 is preferably accomplished with the anvil assembly 34 and cartridge assembly 36 in the open position. Alternately, the anvil and cartridge assemblies can be moved to the clamped position to provide extra stability to the end effector during dissection of tissue. Thereafter, either or both of certain tissue 40 and target tissue 42 can be independently joined and cut by clamping and actuating surgical stapling device 10.

It is noted that although not described in detail, end effector 12 preferably is adapted to access the surgical site through a trocar cannula assembly as is known in the art. To accomplish this, anvil assembly 34 and cartridge assembly 36 are maintained in a clamped position as elongated body portion 18 and end effector 12 are inserted through the cannula (not shown). As illustrated, preferably, dissecting tip 14 does not extend below a plane defined by a bottom surface 36 b of cartridge assembly 36, nor does dissecting tip 14 extend outwardly beyond the sidewalls of cartridge assembly 36. The dissecting tip can be positioned above, preferably slightly above, the plane. As such, surgical stapling device 10 including dissecting tip 14 may be used with a trocar cannula assembly sized to receive a surgical stapling device not having a dissecting tip 14.

FIGS. 6-6 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 114. Dissecting tip 114 is secured to the distal end of end effector 12. Alternately, dissecting tip 114 can be monolithically or integrally formed with end effector 12. As discussed above, end effector 12 includes anvil assembly 34 and cartridge assembly 36. Dissecting tip 114 is secured to a distal surface or portion of anvil assembly 34 in the manner described above with respect to dissecting tip 14. Dissecting tip 114 is also constructed from a surgical grade metal or plastic and includes substantially flat inner and outer surfaces 114 a and 114 b and a rounded, blunt tip 114 c. The use of other known surgically approved materials to construct dissecting tip 114 is envisioned. Other tip configurations may also be employed. The outer edges 114 d of outer surface 114 b are preferably rounded to prevent snagging, and/or cutting of tissue. Inner surface 114 a of dissecting tip 114 is preferably substantially parallel to and spaced from tissue guide surface 36 a of cartridge assembly 36 when anvil assembly 34 and cartridge assembly 36 are in the clamped position. Distal tip 114 c of dissecting tip 114 extends distally beyond the distal end of cartridge assembly 36 and decreases in width from its proximal end to its distal end. The width of the proximal end of dissecting tip 114 is smaller than the width of cartridge assembly 36 and distal tip 114 c preferably does not extend below a plane defined by a bottom surface 36 b of cartridge assembly 36. As such, a surgical stapling device including dissecting tip 114 can be inserted through a trocar cannula assembly sized to receive the stapling device.

The use of dissecting tip 114 is substantially identical to that of dissecting tip 14 and will not be discussed in further detail herein.

FIGS. 7-7 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 214. Dissecting tip 214 is secured onto anvil assembly 34 of end effector 12 in the manner described above with respect to dissecting tip 14. Dissecting tip 214 is also constructed from a surgical grade metal or plastic. Alternatively, the use of other known materials of construction is envisioned.

Dissecting tip 214 includes inner and outer surfaces 214 a and 214 b and a blunt tip 214 c. Inner and outer surfaces 214 a and 214 b preferably each have a substantially flat proximal portion 250 a and 250 b and a substantially flat distal portion 252 a and 252 b positioned at an angle to proximal portion 250. Preferably, proximal portion 250 and distal portion 252 along inner surface 214 a define an angle θ (FIG. 7 a) of between about 10° and about 90°, and most preferably about 30°. The transition between proximal portion 250 a and distal portion 252 a is smooth and rounded to prevent snagging, pulling and/or cutting of tissue. The outer surface of tip 214 can have other shapes, e.g., rounded as in FIGS. 1-5 e. As discussed above with respect to dissecting tips 14 and 114, the width of dissecting tip 214 decreases from its proximal end to its distal end and at its greatest width is less than the width of cartridge assembly 36. The distal end of distal portion 252 a includes a blunt tip 214 c which preferably does not extend beyond a plane defined by a bottom surface 36 b of cartridge assembly 36. The use of dissecting tip 214 is substantially identical to that of dissecting tip 14 and will not be discussed in further detail herein.

FIGS. 8-8 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 314. Dissecting tip 314 includes an inner surface 314 a, a top surface 314 b and a front surface 314 c. Inner surface 314 a is angled and is substantially parallel to distal angled tissue guide surface 36 a of cartridge assembly 36. Top surface 314 b is curved or concave along an axis transverse to a longitudinal axis of anvil assembly 34. Front surface 314 c is angled downwardly towards cartridge assembly 36 and preferably defines an angle θ (FIG. 8 a) of between about 95° and 135° with respect to the longitudinal axis of anvil assembly 34. More preferably, angle θ is about 106°. The width of dissecting tip 314 decreases from a proximal end of dissecting tip 314 to the distal end of dissecting tip 314. The width at the proximal end of dissecting tip 314 is approximately equal to the width of cartridge assembly 36. As discussed above, the dimensions and positioning of dissecting tip 314 on stapling device 10 permit positioning of stapling device 10 through a trocar cannula assembly sized to allow passage stapling device 10.

Distal tip 314 d of dissecting tip 314 is preferably positioned proximally of the distal end of cartridge assembly 36. Alternately, distal tip 314 d may be positioned adjacent to or distally of the distal end of cartridge assembly 36.

Dissecting tip 314 includes a substantially hollow recess 314 e (FIG. 8 f) which is configured to receive the distal end of anvil assembly 34. Dissecting tip 314 may be positioned over the distal end of anvil assembly 34 and secured thereto using any known fastening technique, e.g., adhesives, welding, friction fit, pins, screws, etc. Dissecting tip 314 is preferably formed from surgical grade metals or plastics although other known materials of construction are envisioned. Dissecting tip 314 functions basically in the same manner as discussed above with respect to dissecting tip 14 and will not be discussed in further detail herein.

FIGS. 9-9 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 414. Dissecting tip 414 is similar in shape to dissecting tip 314 but includes a peg extension 436 (FIG. 9 e) to secure dissecting tip 414 to anvil assembly 34, rather than a hollow recess as will be further discussed below. Dissecting tip 414 includes an inner surface 414 a, a top surface 414 b, and a front surface 414 c. Inner surface 414 a preferably is substantially parallel to a tissue guide surface 36 b on the distal end of cartridge assembly 36. Top surface 414 b is flat and is positioned to abut against a distal surface of anvil assembly 34 which is contiguous with an inner tissue engaging surface 34 a of anvil assembly 34. Front surface 414 c is angled downwardly towards cartridge assembly 36 and preferably defines an angle θ (FIG. 9 a) of between about 95° and about 135°. More preferably, angle θ is about 154°.

Peg extension 436 is a T-shaped member which extends upwardly from a proximal end of top surface 414 b of dissecting tip 414. The upper portion 452 of T-shaped member 436 extends transversely across anvil assembly 34 and is dimensioned to be received in a linear slot (not shown) formed in the distal end of anvil assembly 34. To attach dissecting tip 414 to anvil assembly 34, upper portion 452 of T-shaped member 436 is positioned within the distal linear slots of anvil assembly 34 and dissecting tip 414 is rotated 90° to lock upper portion 452 within the linear slot and lock dissecting tip to anvil assembly 34. Additional fastening techniques may be used to fixedly secure dissecting tip 414 to anvil assembly 34, e.g., adhesives, welding, etc.

FIGS. 10-10 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 514. Dissecting tip 514 is substantially similar to dissecting tip 314 in construction but differs in that a distal tip 514 d of dissecting tip 514 is narrower than and positioned above, over or adjacent to the distal end of cartridge assembly 36. Further, front surface 514 c which preferably defines an angle θ (FIG. 10 a) of between about 95° and about 135° is preferably about 115°. As discussed above with respect to dissecting tip 314, dissecting tip 514 defines a hollow recess (not shown) dimensioned and configured to receive the distal end of anvil assembly 34.

FIGS. 11-11 e illustrate yet another preferred embodiment of the presently disclosed dissecting tip shown generally as 614. Dissecting tip 614 is substantially similar to dissecting tip 514 with the exception that dissecting tip 614 includes a pair of cutouts 614 c formed in opposite tapered sidewalls 614 a and 614 b thereof. The tapered sidewalls 614 a and 614 b and cutouts 614 c provide a smooth transition from dissecting tip 614 to anvil assembly 34 to prevent snagging and pulling of tissue.

FIG. 12-12 e illustrate another preferred embodiment of the presently disclosed dissecting tip shown generally as 714. Dissecting tip 714 is formed integrally and/or monolithically with an anvil plate 34 a (FIG. 12 e) of anvil assembly 34 and is therefore preferably formed from a surgical grade metal. Dissecting tip 714 includes an inner surface 714 a, an outer surface 714 b and a distal tip 714 c which preferably is rounded. Inner and outer surfaces 714 a and 714 b are substantially flat and define an angle θ of preferably between about 105° and about 155° in relation to a longitudinal axis of anvil assembly 34. More preferably θ in about 136° Dissecting tip 714 extends downwardly towards cartridge assembly 36, at angle θ which is preferably less than an angle B defined between tissue guide surface 36 a formed on the distal end of cartridge assembly 36 and a longitudinal axis of cartridge assembly 36. Although the invention of this disclosure can be employed on any sized SULU or end effector, for some applications shorter end effectors may be preferred.

It is preferred that the junction, blend or transition of the proximal portion of the inner surface of dissecting tip 14 with the plane of tissue contacting surface 34 of the anvil assembly be axially distal of the junction, blend or transition of tissue guide surface 36 a and the tissue contacting surface of cartridge assembly 36. This provides space to allow tissue to be squeezed distally of the staple working portions of the tissue contacting surfaces of anvil assembly 34 and cartridge assembly 36 and helps maintain the desired tissue gap between those surfaces, during approximation and clamping. The configuration of dissecting tip 714 of end effector 12 shown in FIG. 12 a exemplifies this preferred junctional relationship.

It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the dissecting tip may be secured to other parts of the end effector including the cartridge assembly. Further, each of the dissecting tips may be monolithically or integrally formed with the end effector, e.g., anvil assembly or cartridge assembly. Moreover, the angles and/or curves of the dissecting tip surface(s) may be modified to better suit a particular surgical procedure. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. 

1. A surgical stapling device comprising: an elongated body portion; an end effector including an anvil assembly movably supported in relation to a cartridge assembly between an open position and a clamped position, the cartridge assembly having a plurality of staples supported therein; a dissecting tip extending distally from a distal end of the cartridge assembly, the dissecting tip having a blunt distal end configured to separate target tissue from certain tissue.
 2. A surgical stapling device according to claim 1, wherein the dissecting tip includes smoothly curved inner and outer surfaces.
 3. A surgical stapling device according to claim 2, wherein the distal end of the dissecting tip extends distally beyond the distal end of the anvil assembly.
 4. A surgical stapling device according to claim 3, wherein the curved inner surface is formed by plural curved radii.
 5. A surgical stapling device according to claim 4, wherein the width of the dissecting tip decreases from the proximal end of the dissecting tip to the distal end of the dissecting tip.
 6. A surgical stapling device according to claim 1, wherein the curved inner surface of the dissecting tip is contiguous with an inner tissue contact surface of the cartridge assembly.
 7. A surgical stapling device according to claim 5, wherein the dissecting tip is monolithically formed with the cartridge assembly.
 8. A surgical stapling device according to claim 5, wherein the dissecting tip is secured to the cartridge assembly using a mechanical fastening technique.
 8. A surgical stapling device according to claim 5, wherein the dissecting tip is secured to the cartridge assembly using a mechanical fastening technique. 